<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../lib/vue-2.4.0.js"></script>
</head>

<body>
  <div id="app">
    <div v-show="score >= 90">优秀</div>
    <div v-show="score >= 75 && score < 90">良好</div>
    <div v-show="score >= 60 && score < 75">及格</div>
    <div v-show="score < 60">不及格</div>
    <button @click="delScore">减分</button>
  </div>
</body>
<script>
  let app = new Vue({
    el: '#app',
    data: {
      score: 100
    },
    methods: {
      delScore() {
        this.score -= 10
      }
    }
  })
</script>

</html>